[PATCH AUTOSEL 5.8 51/53] iommu/amd: Do not force direct mapping when SME is active

[PATCH AUTOSEL 5.8 51/53] iommu/amd: Do not force direct mapping when SME is active

[Sasha Levin]

From: Joerg Roedel <jroedel@suse.de>

[ Upstream commit 7cad554887f1c5fd77e57e6bf4be38370c2160cb ]

Do not force devices supporting IOMMUv2 to be direct mapped when memory
encryption is active. This might cause them to be unusable because their
DMA mask does not include the encryption bit.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Link: https://lore.kernel.org/r/20200824105415.21000-2-joro@8bytes.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/iommu/amd/iommu.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 2f22326ee4dfe..547b41e376574 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -2650,7 +2650,12 @@ static int amd_iommu_def_domain_type(struct device *dev)
 	if (!dev_data)
 		return 0;
 
-	if (dev_data->iommu_v2)
+	/*
+	 * Do not identity map IOMMUv2 capable devices when memory encryption is
+	 * active, because some of those devices (AMD GPUs) don't have the
+	 * encryption bit in their DMA-mask and require remapping.
+	 */
+	if (!mem_encrypt_active() && dev_data->iommu_v2)
 		return IOMMU_DOMAIN_IDENTITY;
 
 	return 0;
-- 
2.25.1

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[PATCH AUTOSEL 5.8 52/53] iommu/amd: Do not use IOMMUv2 functionality when SME is active

[Sasha Levin]

From: Joerg Roedel <jroedel@suse.de>

[ Upstream commit 2822e582501b65707089b097e773e6fd70774841 ]

When memory encryption is active the device is likely not in a direct
mapped domain. Forbid using IOMMUv2 functionality for now until finer
grained checks for this have been implemented.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Link: https://lore.kernel.org/r/20200824105415.21000-3-joro@8bytes.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/iommu/amd/iommu_v2.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/iommu/amd/iommu_v2.c b/drivers/iommu/amd/iommu_v2.c
index e4b025c5637c4..5a188cac7a0f1 100644
--- a/drivers/iommu/amd/iommu_v2.c
+++ b/drivers/iommu/amd/iommu_v2.c
@@ -737,6 +737,13 @@ int amd_iommu_init_device(struct pci_dev *pdev, int pasids)
 
 	might_sleep();
 
+	/*
+	 * When memory encryption is active the device is likely not in a
+	 * direct-mapped domain. Forbid using IOMMUv2 functionality for now.
+	 */
+	if (mem_encrypt_active())
+		return -ENODEV;
+
 	if (!amd_iommu_v2_supported())
 		return -ENODEV;
 
-- 
2.25.1

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